Gauge Newsletter January 2020 | Page 49

Skyscrapers or Tall Buildings? Generally, ‘Tall buildings’ are becoming more indispensable structures all over the world nowadays. It is a solution for the increasing population density of urban areas and can be used as multipurpose buildings. And also, it adds more attraction to the cities as iconic landmarks. Furthermore, many countries which are known to be wealthy and powerful and as well as the countries which are reaching that state, tend to construct structures like ‘skyscrapers’ to show their power and wealth. Therefore, it has become a global race. Even though we interchangeably use the terms ‘Tall’ and ‘Skyscraper’ to describe the structures which are notable for their heights compared with other structures, there is a difference between buildings of ‘Tall or High- Rise Buildings’ and ‘Skyscrapers’. To qualify as a skyscraper, a structure must be self-supporting and must not require tension cables or supports to remain standing Often the tallest structures in a city, communication and observation towers aren’t typically classed as skyscrapers and there should be at least 50% of occupied space of the structure’s total height. Therefore, although they are the tallest structures in the city, communication and observation towers are not normally considered as skyscrapers if they do not meet this 50% threshold. Moreover, skyscrapers must rise to a minimum height of 150m (492 feet). According to the Council on Tall Buildings and Urban Habitats (CTBUH), there is no absolute definition for a tall building. A building is considered to be tall under one or more of the following categories. • Height Relative Context - A 14-storey building might not be considered to be tall in a high-rise city like Hong Kong or Chicago but in a suburban area, this might be taller than other buildings. • Proportion – There are numerous buildings that are not particularly high but adequately give the appearance of a tall building. On the other hand, there are numerous buildings that are quite high but their floor area rules them out of being classified as a tall building. • Embracing Technologies Relevant to Tall Buildings – A building which has specific vertical transport technologies, structural wind bracing as a product of height, etc. might be considered as a tall building. Although the number of floors is a poor indicator of defining a building height, a building with 14 or more storeys or rise more than 50m in height could be typically used as the threshold for a tall building. GAUGE Magazine University of Peradeniya Page 47